var format_active = function (value,row,index) {
    if(value){
        return '<span class="icon-ok" style="width: 16px;height: 16px;display: inline-block;"></span>';
    }else{
        return '<span class="icon-stop" style="width: 16px;height: 16px;display: inline-block;"></span>';
    }
}

var format_icon = function (value,row,index) {
    return '<span class="$value">123</span>';
}